Hydrometer



June 10, 1952 K. WEISS 2,600,035

HYDROMETER Filed March 15, 1950 INVENTOR Karl We/ss BY w y/094 ATTOR NEYS Patented June 10, 1952" UNITED STATES PATENT OFFICE 1 Claim.

This invention relates to hydrometers and aims to provide improved means for anchoring fused metal ballast in the glass bulb.

Another object of the invention is to provide a streamlined bulb having an anchoring pin fused in the bottom of the ballast chamber to prevent any displacement of the fused ballast alloy.

Still another object of the invention is to provide a stream-lined glass bulb having a glass pin fused in the bottom of the ballast chamber and provided with a head at its upper end adapted to be submerged in molten ballast to provide an anchor therefor.

Other objects and advantages of the invention will appear in the following specification, when considered in connection with the accompanying drawing, wherein:

Fig. 1 is a side elevation, partly in section, showing an hydrometer embodying the invention; and

Fig. 2 is a fragmentary elevation, on an enlarged scale, showing the preferred form of anchoring pin in the ballast chamber.

Referring now particularly to the drawing, the hydrometer is shown as having the usual cylindrical bulb 10, with a rounded and reduced upper end carrying an ordinary tubular stem 1 I carrying a calibrated scale 12.

A stream-lined ballast chamber I4, in the form of an inverted cone, is first formed on the bottom of the cylindrical bulb by blowing and drawing the glass in the usual manner. It i sealed by fusing the tip over a Bunsen burner. Then, a short glass pin l5 having an enlarged head I6 is dropped into the chamber and its lower end is fused into the tip portion by slowly spinning the bulb over a Bunsen flame to keep the pin centered or coaxial with the bulb; although, it is not essential that the pin be coaxial with the ballast chamber. The reduced bottom end of the ballast chamber will support the pin almost in a vertical position when it is dropped into place. When the 2 pin is thus assembled, the stem is set on the bulb and pellets of th ballast alloy are dropped into the chamber and melted to submerge the pin, as shown in Fig. 1. When the ballast alloy solidifies, it is firmly and securely anchored in place.

Obviously, the anchor pin may be formed by die casting or moulding. It is preferably made by fusing a glass rod at one end and the head may be formed by pressing the plastic heated end on a heated anvil or surface, in a mannerwell known to those skilled in the art. Care is taken to select glass of the same type as the glass in the bulb, to avoid breakage, due to differences in the coefiicients of expansion.

From the foregoing description, it will be seen that the invention provides a simple and effective ballast anchor which is easy to apply to streamlined hydrometers.

Obviously, the invention is not restricted to the particular embodiment thereof, herein shown and described.

What is claimed is:

In a glass hydrometer having a cylindrical bulb with a streamlined ballast chamber, an anchoring pin consisting of a solid glass rod with a flattened head at its upper end fused at its lower end into the tip of the ballast chamber; and solid metal ballast in the chamber anchored in place by said pin.

KARL WEISS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,935,703 Fairchild et a1 Nov. 21, 1933 2,020,968 Ruehfel Nov. 12, 1935 2,035,603 Hurlburt Mar. 31, 1936 2,180,995 Nurnberg Nov. 21, 1939 

